Meaning
Mineral filler concentration defines the mass fraction of calcium carbonate added to a base polymer resin during compounding. This calcium carbonate loading alters the density, stiffness, and thermal conductivity of the resulting plastic material. Precise control prevents excessive brittleness in the final moulded part.
Processing Impact
Manufacturers introduce this particulate material during the extrusion phase to reduce total resin costs while improving dimensional stability. High inclusion levels increase the wear on screw and barrel surfaces inside the injection moulding equipment. These abrasive characteristics shorten the service life of metallic components when compared to virgin resin processing.
Technicians adjust the feed rate to ensure uniform dispersion across every production batch.
Material Specification
Resin datasheet values provide an upper threshold for filler content that maintains mechanical performance standards. Moulders often target a value slightly below this maximum to compensate for variability in raw material feed systems. Virgin compounds maintain consistent particle size distribution throughout the storage life.
Regrind material containing high concentrations of filler experiences significant degradation of impact strength over repeated heat cycles.
Economic Consequence
Added minerals substitute for more expensive synthetic polymers to lower the unit cost of high volume commodities. Profit margins depend on the trade off between the low cost of the filler and the physical property requirements of the finished component. Excess filler accumulation causes localized weld line weakness in complex geometric designs.
Final part integrity relies on the chemical compatibility between the inorganic particles and the continuous polymer phase.
